Small Engine Troubleshooting Problems? Ask a Mechanic Now.
Hi, my name is***** will be assisting you.
This sounds like the unloader valve in the pump is stuck causing you to have no pressure or pulsating pressure. This can happen while sitting in storage if you don't use a pump saver to prior to putting the machine away for storage. The pump saver helps to clean the pump and lubricate if for proper storage when in off season storage. You may be able to remove the unloader valve and clean it good and make it work again, however you may end up having to replace it. It is important to remove the seat that is just below the valve as well and make sure that it is clean.
If you can provide the model and serial number from the frame of the machine I can help you with more specific information.